Natsume is implored to help spirits who are currently being exorcised. He finds a kindred spirit in Tanuma, a boy who also senses spirits although not as powerful as Natsume.

Natsume encounters a spirit who was enslaved by his grandmother Reiko 50 years ago by writing his name on a torn page from the Book of Friends, and tying it to a tree in a forest. Can Natsume help locate the torn page? What was Reiko's intention of tying it to a tree?

(Source: Wikipedia)

Natsume encounters a young boy named Kai sealed in a coffin in an abandoned house. Natsume sets Kai free and finds out that Kai is being stalked by a youkai. After a time, Natsume becomes the target of this youkai and stops the youkai's stalking with Nyanko-sensei's help. In the end Natori who turns out to be the stalker and who sealed Kai in the coffin, tells Natsume that Kai is a Youkai.

(Source: Wikipedia)